Analyte Sensors and Methods of Making and Using the Same

• US 20100230285A1
• Filed: 02/26/2010
• Published: 09/16/2010
• Est. Priority Date: 02/26/2009
• Status: Abandoned Application

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Hoss, Udo, Hayter, Gary Alan, McGarraugh, Geoffrey V., Thomas, Christopher Allen
• Application Number:
  US12/714,439
• Publication Number:
  US 20100230285A1
• Time in Patent Office: Days
• US Class Current: 204/415
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771

Abstract

Methods and systems for providing continuous analyte monitoring including in vivo sensors that do not require any user calibration during in vivo use are provided. Also provided are methods and devices including continuous analyte monitoring systems that include in vivo sensors which do not require any system executed calibration or which do not require any factory based calibration, and which exhibit stable sensor sensitivity characteristics. Methods of manufacturing the no calibration sensors and post manufacturing packaging and storage techniques are also provided.

Claims

1. An analyte sensor, comprising:

a substrate;

a conductive layer disposed over at least a portion of the substrate;

a dielectric layer disposed over the conductive layer and having a void therein; and

a sensing layer disposed within the void, wherein the area of the sensing layer in contact with the conductive layer has a sensor-to-sensor coefficient of variation of less than approximately 5% within a sensor lot.

2. The analyte sensor of claim 1 wherein the coefficient of variation is less than approximately 3% within the sensor lot.

3. The analyte sensor of claim 1 further including a membrane disposed over the area of the sensing layer in contact with the conductive layer, wherein the membrane has a defined thickness with a sensor to sensor coefficient of variation of less than approximately 5% within the sensor lot.

4. The analyte sensor of claim 3 wherein the coefficient of variation is less than approximately 3% within the sensor lot.

5. The analyte sensor of claim 3 wherein the membrane disposed over the area of the sensing layer in contact with the conductive layer has a substantially uniform thickness.

6. The analyte sensor of claim 3 wherein the membrane disposed over the area of the sensing layer in contact with the conductive layer has a substantially uniform distribution.

7. The analyte sensor of claim 3 wherein the membrane has a low oxygen permeability.

8. The analyte sensor of claim 1 wherein the area of the sensing layer in contact with the conductive layer substantially defines an active area of the sensor.

9. The analyte sensor of claim 1, wherein the void is located over a distal portion of the conductive layer.

10. The analyte sensor of claim 1 wherein the conductive layer in contact with the sensing layer defines at least a portion of a working electrode of the analyte sensor.

11. The analyte sensor of claim 1 wherein the conductive layer includes one or more of vitreous carbon, graphite, silver, silver-chloride, platinum, palladium, platinum-iridium, titanium, gold or, iridium.

12. The analyte sensor of claim 1 wherein the dielectric layer includes a photo-imageable polymeric material.

13. The analyte sensor of claim 1 wherein the dielectric layer includes a photo-imageable film disposed over the conductive layer and at least a portion of the substrate.

14. The analyte sensor of claim 1 wherein the void is formed by a photolithographic process.

15. The analyte sensor of claim 1 further including one or more of a glucose flux limiting layer, an interference layer or a biocompatible layer disposed over the void.

16. The analyte sensor of claim 1 wherein the area of the sensing layer in contact with the conductive layer is about 0.01 mm² to about 1.0 mm².

17. The analyte sensor of claim 1 wherein the area of the sensing layer in contact with the conductive layer is about 0.04 mm² to about 0.36 mm².

18. The analyte sensor of claim 1 wherein the surface area of the sensing layer in contact with the conductive layer on the substrate is substantially fixed.

19. The analyte sensor of claim 1 wherein the dimension of the void formed in the dielectric layer is substantially fixed.

20. An analyte sensor, comprising:

a substrate having a distal portion;

a conductive layer disposed over at least a portion of the distal portion of the substrate;

a dielectric layer disposed over the conductive layer and having a void therein such that the location of the void coincides with the distal portion of the substrate; and

a sensing layer disposed within the void, wherein the area of the sensing layer in contact with the conductive layer has a sensor-to-sensor coefficient of variation of less than approximately 5% within a sensor lot;

wherein the distal portion of the substrate is maintained in fluid contact with an interstitial fluid over a predetermined time period.

21. The analyte sensor of claim 20 wherein the predetermined time period is about three days or more.

22. The analyte sensor of claim 20 wherein the area of the sensing layer in contact with the conductive layer defines at least a portion of a working electrode of the analyte sensor in fluid contact with the interstitial fluid over the predetermined time period.

23. The analyte sensor of claim 20 wherein the analyte sensor further includes a membrane disposed over the area of the sensing layer in contact with the conductive layer, wherein the membrane has a defined thickness with a sensor to sensor coefficient of variation of less than approximately 5% within the sensor lot.

24. The analyte sensor of claim 23 wherein the membrane disposed over the area of the sensing layer in contact with the conductive layer has a substantially uniform thickness.

25. The analyte sensor of claim 23 wherein the membrane disposed over the area of the sensing layer in contact with the conductive layer has a substantially uniform distribution.

26. The analyte sensor of claim 20 wherein the surface area of the sensing layer in contact with the conductive layer on the substrate is substantially constant between sensors in the sensor lot.

27. The analyte sensor of claim 20 wherein the dimension of the void formed in the dielectric layer is substantially constant between sensors in the sensor lot.

28. The analyte sensor of claim 20 further including one or more of a glucose flux limiting layer, an interference layer or a biocompatible layer disposed over the void.